Friday, March 31, 2017

Just thought I'd share these pics that I took at STAPLES Center in Los Angeles two days ago—when I visited the new bronze statue of 4-time NBA champion Shaquille O'Neal that is now on display at Star Plaza outside the arena. The statue, which is 9-feet-tall and weighs 1,200 pounds, was unveiled before the Lakers' home game against the Minnesota Timberwolves on March 24 (the Lakers won that game in overtime, 130-119). It's only a matter of time till Kobe Bryant himself gets his own statue outside STAPLES Center...and I'll be dishin' out 7 dollars (like I did on Wednesday) for parking before I walk over to the stadium to see the Black Mamba immortalized at Star Plaza as well. Happy Friday!

Thursday, March 30, 2017

NASA's MAVEN Reveals Most of Mars' Atmosphere Was Lost to Space (Press Release)

Solar wind and radiation are responsible for stripping the Martian atmosphere, transforming Mars from a planet that could have supported life billions of years ago into a frigid desert world, according to new results from NASA's MAVEN spacecraft.

"We've determined that most of the gas ever present in the Mars atmosphere has been lost to space," said Bruce Jakosky, principal investigator for the Mars Atmosphere and Volatile Evolution Mission(MAVEN), University of Colorado in Boulder. The team made this determination from the latest results, which reveal that about 65 percent of the argon that was ever in the atmosphere has been lost to space. Jakosky is lead author of a paper on this research to be published in Science on Friday, March 31.

In 2015, MAVEN team members previously announced results that showed atmospheric gas is being lost to space today and described how atmosphere is stripped away. The present analysis uses measurements of today’s atmosphere for the first estimate of how much gas was lost through time.

Liquid water, essential for life, is not stable on Mars' surface today because the atmosphere is too cold and thin to support it. However, evidence such as features resembling dry riverbeds and minerals that only form in the presence of liquid water indicates the ancient Martian climate was much different – warm enough for water to flow on the surface for extended periods.

“This discovery is a significant step toward unraveling the mystery of Mars' past environments,“ said Elsayed Talaat, MAVEN Program Scientist, at NASA Headquarters in Washington. “In a broader context, this information teaches us about the processes that can change a planet’s habitability over time.”

There are many ways a planet can lose some of its atmosphere. For example, chemical reactions can lock gas away in surface rocks, or an atmosphere can be eroded by radiation and a stellar wind from a planet's parent star. The new result reveals that solar wind and radiation were responsible for most of the atmospheric loss on Mars, and the depletion was enough to transform the Martian climate. The solar wind is a thin stream of electrically conducting gas constantly blowing out from the surface of the Sun.

The early Sun had far more intense ultraviolet radiation and solar wind, so atmospheric loss by these processes was likely much greater in Mars' history. According to the team, these processes may have been the dominant ones controlling the planet's climate and habitability. It's possible microbial life could have existed at the surface early in Mars’ history. As the planet cooled off and dried up, any life could have been driven underground or forced into rare surface oases.

Jakosky and his team got the new result by measuring the atmospheric abundance of two different isotopes of argon gas. Isotopes are atoms of the same element with different masses. Since the lighter of the two isotopes escapes to space more readily, it will leave the gas remaining behind enriched in the heavier isotope. The team used the relative abundance of the two isotopes measured in the upper atmosphere and at the surface to estimate the fraction of the atmospheric gas that has been lost to space.

As a "noble gas" argon cannot react chemically, so it cannot be sequestered in rocks; the only process that can remove noble gases into space is a physical process called "sputtering" by the solar wind. In sputtering, ions picked up by the solar wind can impact Mars at high speeds and physically knock atmospheric gas into space. The team tracked argon because it can be removed only by sputtering. Once they determined the amount of argon lost by sputtering, they could use this information to determine the sputtering loss of other atoms and molecules, including carbon dioxide (CO2).

CO2 is of interest because it is the major constituent of Mars' atmosphere and because it's an efficient greenhouse gas that can retain heat and warm the planet. "We determined that the majority of the planet's CO2 was also lost to space by sputtering," said Jakosky. "There are other processes that can remove CO2, so this gives the minimum amount of CO2 that's been lost to space."

The team made its estimate using data from the Martian upper atmosphere, which was collected by MAVEN's Neutral Gas and Ion Mass Spectrometer (NGIMS). This analysis included measurements from the Martian surface made by NASA's Sample Analysis at Mars (SAM) instrument on board the Curiosity rover.

"The combined measurements enable a better determination of how much Martian argon has been lost to space over billions of years," said Paul Mahaffy of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Using measurements from both platforms points to the value of having multiple missions that make complementary measurements." Mahaffy, a co-author of the paper, is principal investigator on the SAM instrument and lead on the NGIMS instrument, both of which were developed at NASA Goddard.

The research was funded by the MAVEN mission. MAVEN's principal investigator is based at the University of Colorado's Laboratory for Atmospheric and Space Physics, Boulder, and NASA Goddard manages the MAVEN project. MSL/Curiosity is managed by NASA's Jet Propulsion Laboratory, Pasadena, California.

Monday, March 27, 2017

This enhanced-color image of a mysterious dark spot on Jupiter seems to reveal a Jovian “galaxy” of swirling storms.

Juno acquired this JunoCam image on Feb. 2, 2017, at 5:13 a.m. PDT (8:13 a.m. EDT), at an altitude of 9,000 miles (14,500 kilometers) above the giant planet’s cloud tops. This publicly selected target was simply titled “Dark Spot.” In ground-based images it was difficult to tell that it is a dark storm.

Citizen scientist Roman Tkachenko enhanced the color to bring out the rich detail in the storm and surrounding clouds. Just south of the dark storm is a bright, oval-shaped storm with high, bright, white clouds, reminiscent of a swirling galaxy. As a final touch, he rotated the image 90 degrees, turning the picture into a work of art.

Friday, March 24, 2017

Despite having seven years to craft an alternative healthcare bill that wouldn't suck, the GOP dropped the ball anyway when it couldn't muster enough votes needed to pass the American Health Care Act (AHCA) earlier today. I would like to thank the Freedom Caucus (an ultra-conservative group of Republicans in the House of Representatives) for being so heartless in their attempt to strip away components of AHCA that would provide basic medical needs to pregnant women and sick individuals that sensible Republicans (yes, I too can't believe that such a group exists in the U.S. government) couldn't support the legislation if the Freedom Caucus had its way. I would also like to thank Donald Trump for undermining his presidency by not being able to repeal and replace the Affordable Care Act (a.k.a. Obamacare) 64 days after he was sworn into the White House...despite saying during his presidential campaign that he would accomplish the feat on Day One of his first (and only?) term in office. And House Speaker Paul Ryan showed that he is as ineffective a leader in his party as he is a spineless patsy to Trump.

NASA / Bill Ingalls

But if I'm gonna say some nice things about Trump, it's that at least he signed the NASA Transition Authorization Act of 2017 last Tuesday. This bill calls for a $19.5 billion budget for NASA in 2018...which supports the Europa Clipper mission to Jupiter, the Mars 2020 rover that is Curiosity's successor, and a manned mission to the Red Planet by 2033. So thanks to Obamacare being left intact (and in Paul Ryan's words, remaining "the law of the land"), 24 million Americans who would've lost their health coverage under AHCA by 2026 will (hopefully) be alive to see humans set foot on (or at least orbit) the Red Planet in a little over 15 years! Awesome.

And of course, thanks to the demise of AHCA, I'll still be able to take medication without any issues for the illness, known as Valley Fever (or Coccidioidomycosis), that I contracted five years ago. To the Republican Party: Your utter incompetence saved the lives of many Americans today...including possibly mine. Thank you.

Wednesday, March 22, 2017

Dwarf planet Ceres may be hundreds of millions of miles from Jupiter, and even farther from Saturn, but the tremendous influence of gravity from these gas giants has an appreciable effect on Ceres' orientation. In a new study, researchers from NASA's Dawn mission calculate that the axial tilt of Ceres -- the angle at which it spins as it journeys around the Sun -- varies widely over the course of about 24,500 years. Astronomers consider this to be a surprisingly short period of time for such dramatic deviations.

Changes in axial tilt, or "obliquity," over the history of Ceres are related to the larger question of where frozen water can be found on Ceres' surface, scientists report in the journal Geophysical Research Letters. Given conditions on Ceres, ice would only be able to survive at extremely cold temperatures -- for example, in areas that never see the Sun.

"We found a correlation between craters that stay in shadow at maximum obliquity, and bright deposits that are likely water ice," said Anton Ermakov, postdoctoral researcher at NASA's Jet Propulsion Laboratory, Pasadena, California, and lead author of the study. "Regions that never see sunlight over millions of years are more likely to have these deposits."

Cycles of Obliquity

Throughout the last 3 million years, Ceres has gone through cycles where its tilt ranges from about 2 degrees to about 20 degrees, calculations indicate.

"We cannot directly observe the changes in Ceres' orientation over time, so we used the Dawn spacecraft's measurements of shape and gravity to precisely reconstruct what turned out to be a dynamic history," said Erwan Mazarico, a co-author at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

The last time the dwarf planet reached a maximum tilt, which was about 19 degrees, was 14,000 years ago, researchers said. For comparison, Earth is tilted 23.5 degrees. This significant tilt causes our planet to experience seasons: The northern hemisphere experiences summer when it is oriented toward the Sun, and winter when it's pointed away from the Sun. By contrast, Ceres' current tilt is about 4 degrees, so it will not have such strong seasonal effects over the course of a year there (which is about 4.6 Earth years).

How Obliquity Relates to Ice

When the axial tilt is small, relatively large regions on Ceres never receive direct sunlight, particularly at the poles. These persistently shadowed regions occupy an area of about 800 square miles (2,000 square kilometers). But when the obliquity increases, more of the craters in the polar regions receive direct exposure to the Sun, and persistently shadowed areas only occupy 0.4 to 4 square miles (1 to 10 square kilometers). These areas on Ceres' surface, which stay in shadow even at high obliquity, may be cold enough to maintain surface ice, Dawn scientists said.

These craters with areas that stay in shadow over long periods of time are called "cold traps," because they are so cold and dark that volatiles -- substances easily vaporized -- that migrate into these areas can't escape, even over a billion years. A 2016 study by the Dawn team in Nature Astronomy found bright material in 10 of these craters, and data from Dawn's visible and infrared mapping spectrometer indicate that one of them contains ice.

The new study focused on polar craters and modeled how shadowing progresses as Ceres' axial tilt varies. In the northern hemisphere, only two persistently shadowed regions remain in shadow at the maximum 20-degree tilt. Both of these regions have bright deposits today. In the southern hemisphere, there are also two persistently shadowed regions at highest obliquity, and one of them clearly has a bright deposit.

Shadowed Regions in Context

Ceres is the third body in the solar system found to have permanently shadowed regions. Mercury and Earth's Moon are the other two, and scientists believe they received their ice from impacting bodies. However, Mercury and the Moon do not have such wide variability in their tilts because of the stabilizing gravitational influence of the Sun and Earth, respectively. The origin of the ice in Ceres' cold traps is more mysterious -- it may come from Ceres itself, or may be delivered by impacts from asteroids and comets. Regardless, the presence of ice in cold traps could be related to a tenuous water atmosphere, which was detected by ESA's Herschel Space Observatory in 2012-13. Water molecules that leave the surface would fall back onto Ceres, with some landing in cold traps and accumulating there.

"The idea that ice could survive on Ceres for long periods of time is important as we continue to reconstruct the dwarf planet's geological history, including whether it has been giving off water vapor," said Carol Raymond, deputy principal investigator of the Dawn mission and study co-author, based at JPL.

Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.

Friday, March 17, 2017

Happy St. Patrick's Day! Just thought I'd share these photos that I took of the Shamrock Shake that I bought at McDonald's a little over two weeks ago. It's totally delicious! I've been meaning to try out this minty beverage since 2012...but was unable to due to this unfortunate situation that I was in during March of that year. Well, better late than never!

Thursday, March 16, 2017

Demanding electric, magnetic and power requirements, harsh radiation, and strict planetary protection rules are some of the critical issues that had to be tackled in order to move ESA’s Jupiter Icy Moons Explorer – Juice – from the drawing board and into construction.

Scheduled for launch in 2022, with arrival in the Jovian system in 2029, Juice will spend three-and-a-half years examining the giant planet’s turbulent atmosphere, enormous magnetosphere, its set of tenuous dark rings and its satellites.

It will study the large icy moons Ganymede, Europa and Callisto, which are thought to have oceans of liquid water beneath their icy crusts – perhaps even harbouring habitable environments.

The mission will culminate in a dedicated, eight-month tour around Ganymede, the first time any moon beyond our own has been orbited by a spacecraft.

Juice will be equipped with 10 state-of-the-art instruments, including cameras, an ice-penetrating radar, an altimeter, radio-science experiments, and sensors to monitor the magnetic fields and charged particles in the Jovian system.

In order to ensure it can address these goals in the challenging Jovian environment, the spacecraft’s design has to meet stringent requirements.

An important milestone was reached earlier this month, when the preliminary design of Juice and its interfaces with the scientific instruments and the ground stations were fixed, which will now allow a prototype spacecraft to be built for rigorous testing.

The review also confirmed that the 5.3 tonne spacecraft will be compatible with its Ariane 5 launcher.

Operating in the outer Solar System, far from the Sun, means that Juice needs a large solar array: two wings of five panels each are foreseen, which will cover a total surface area of nearly 100 square metres, capable of providing 820 Watts at Jupiter by the end of the mission.

After launch, Juice will make five gravity-assist flybys in total: one each at Mars and Venus, and three at Earth, to set it on course for Jupiter. Its solar panels will have to cope with a range of temperatures such that when it is flying closer to the Sun during the Venus flyby, the solar wings will be tilted to avoid excessive temperatures damaging the solar cells.

The spacecraft’s main engine will be used to enter orbit around the giant planet, and later around Jupiter’s largest moon, Ganymede. As such, the engine design has also been critically reviewed at this stage.

Special measures will allow Juice to cope with the extremely harsh radiation that it must endure for several years around Jupiter. This means careful selection of components and materials, as well as radiation shielding.

One particularly important topic is Juice’s electromagnetic ‘cleanliness’. Because a key goal is to monitor the magnetic fields and charged particles at Jupiter, it is imperative that any electromagnetic fields generated by the spacecraft itself do not interfere with the sensitive scientific measurements.

This will be achieved by the careful design of the solar array electrical architecture, the power distribution unit, and the reaction wheels – a type of flywheel that stabilises the attitude.

The review also ensured that Juice will meet strict planetary protection guidelines, because it is imperative to minimise the risk that the potentially habitable ocean moons, particularly Europa, might be contaminated by viruses, bacteria or spores carried by the spacecraft from Earth. Therefore, mission plans ensure that Juice will not crash into Europa, on a timescale of hundreds of years.

“The spacecraft design has been extensively and positively reviewed, and confirmed to address the many critical mission requirements,” says Giuseppe Sarri, Juice project manager. “So far we are on schedule, and are delighted to begin the development stage of this ambitious large-class mission.”

ESA’s industrial partners, led by Airbus, now have the go-ahead to start building the prototype spacecraft units that will subjected to tough tests to simulate the conditions expected during launch, as well as the extreme range of environmental conditions.

Once the design is proved beyond doubt, the flight model – the one that will actually go into space – will be built.

Sunday, March 12, 2017

Yesterday, I went to The Grove near Beverly Hills to attend a discussion and book signing by Lily Collins...the daughter of music legend Phil Collins and an up-and-coming actress who appeared in such films as last year's Rules Don't Apply, 2013's The Mortal Instruments: City of Bones and the 2009 Oscar-nominated movie The Blind Side. Ms. Collins was totally awesome in person. She read an excerpt from her new book Unfiltered before giving her take on it and talking about what motivated her to write her first publication. Afterwards, she spent the next two hours signing copies of her book and taking pics with around 300 fans who drove to Barnes & Noble to see her in person. Some attendees even flew 2,000 miles to see Ms. Collins in Los Angeles... Pretty cool!

There are two other book signings that I plan to attend this May—but I won't mention the people appearing since I don't want to jinx these events. Carry on!

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory in Pasadena, California, manages the mission for the agency's Science Mission Directorate in Washington. The Cassini imaging operations center is based at the Space Science Institute in Boulder, Colorado. Caltech in Pasadena manages JPL for NASA.

Thursday, March 09, 2017

NASA's upcoming mission to investigate the habitability of Jupiter's icy moon Europa now has a formal name: Europa Clipper.

The moniker harkens back to the clipper ships that sailed across the oceans of Earth in the 19th century. Clipper ships were streamlined, three-masted sailing vessels renowned for their grace and swiftness. These ships rapidly shuttled tea and other goods back and forth across the Atlantic Ocean and around globe.

In the grand tradition of these classic ships, the Europa Clipper spacecraft would sail past Europa at a rapid cadence, as frequently as every two weeks, providing many opportunities to investigate the moon up close. The prime mission plan includes 40 to 45 flybys, during which the spacecraft would image the moon's icy surface at high resolution and investigate its composition and the structure of its interior and icy shell.

Europa has long been a high priority for exploration because it holds a salty liquid water ocean beneath its icy crust. The ultimate aim of Europa Clipper is to determine if Europa is habitable, possessing all three of the ingredients necessary for life: liquid water, chemical ingredients, and energy sources sufficient to enable biology.

"During each orbit, the spacecraft spends only a short time within the challenging radiation environment near Europa. It speeds past, gathers a huge amount of science data, then sails on out of there," said Robert Pappalardo, Europa Clipper project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.

Previously, when the mission was still in the conceptual phase, it was sometimes informally called Europa Clipper, but NASA has now adopted that name as the former title for the mission.

The mission is being planned for launch in the 2020s, arriving in the Jupiter system after a journey of several years.

JPL manages the mission for the agency's Science Mission Directorate in Washington.